富碲化物型金矿形成的物理化学条件——以水泉沟金矿田为例  

PHYSICOCHEMICAL CONDITIONS FOR THE FORMATION OF TELLURIDES RICH GOLD DEPOSITS AS EXEMPLIFIED BY THE SHUIQUANGOU GOLD OREFIELD

作　　者：张招崇[1] 李兆鼐[1] 

机构地区：[1]中国地质科学院地质研究所

出　　处：《矿床地质》1997年第1期41-52,共12页Mineral Deposits

摘　　要：通过对冀北水泉沟金矿田与偏碱性岩有关的富碲化物型金矿和不含碲化物金矿床的地质特征、黄铁矿的标型特征以及流体包裹体成分的对比分析，揭示了富碲化物型金矿的某些共同特征及其所指示的物理化学条件。同时利用热力学分析，从理论上阐明了这些现象的内在原因，并提出其形成需要三个条件：①高碲的地球化学背景场；②有利于碲活化和迁移的物理化学条件（酸性）；③有利于碲化物沉淀的物理化学条件：低温。With the Shuiquangou gold orefield as the example, the authors have studied the physi cochemical conditions for the formation of tellurides rich gold deposite. Located on the southern side of the Shangyi Chongli Chicheng deep fault (the boundary between Inner Mongolia geoaxis and Yanshan subsidence zone) in central northern margin of the North China platform, the Shuaquangou gold orefield is intimately related to Shuiquangou slightly alkaline complex in time and space. With the exception of the Jinjiazhuang gold deposit, all the gold deposits in the orefield are tellurides rich type ones characterized commonly by high gold fineness, low sulfide content, {100} crystal form for pyrite, dominant Cl - and low concentration of SO 2- 4 in ore fluids, with the first feature indicating high Te 2 fugacity and the last three suggesting low S 2 fugacity. So far as physicochemical conditions are concerned, thermodynamic analysis shows that low pH values are favorable for the mobilization and migration of Te, whereas low temperature, high Te fugacity and high f Te 2 / f S 2 ratios are favorable for the precipitation of tellurides. Based on these understanding combined with regional distribution of tellurides rich gold deposits and geochemical background of Te, the authors have advanced three prerequisites for the formation of tellurides rich gold deposits and also pointed out that between alkaline rocks and tellurides rich gold deposits there exists indirect organic connection rather than the simple direct magmatic differentiation and evolution relationship.

关 键 词：金矿床 形成 物理化学条件 

分 类 号：P618.510.5[天文地球—矿床学] P618.510.4[天文地球—地质学]